Exemplary aspects of the present invention relate to a projector, and specifically, to a projector technology using solid light emitting elements as light source parts.
A light source using solid light emitting elements has been used as a light source of a projector. Among the solid light emitting elements, the progress in development and enhancement of a light emitting diode (hereinafter, “LED”) is significant. In addition to low-power LED products for display, high-power LED products for illumination are being developed. The LED is characterized by having a micro-miniature form, ultralight weight, and long life. From these features, the LED may be used especially for a light source of a compact portable projector. Further, the LED can supply illumination light with high color purity having a specific wavelength range. Accordingly, by using LEDs having different wavelength characteristics from each other as light sources of a projector, a color image with high color reproducibility can be obtained.
In the present circumstances, the efficiency of an LED obtained by rated current is on the order of ½ to ⅓ of that of an ultra high pressure mercury lamp. Accordingly, in the case of using an LED for a projector, it is necessary to form a construction by which a large amount of light is obtained. The rated current of the LED depends on the amount of heat generation of the LED. By efficiently releasing heat from the LED, the rated current can be made larger. Accordingly, a large amount of light can be obtained by forming a projector with high heat release efficiency. Constructions for realizing efficient heat release by cooling a light source in an image display device or the like are proposed in Publication of Japanese Patent Application No. Hei-5-2215 and Publication of Japanese Utility Model Application No. Sho-62-55456.